Polonium-210 causes a very clear association with radiation. And this is not for nothing, since it is extremely dangerous.
Its existence was predicted as far back as 1889.Mendeleev, when he created his famous periodic table. In practice, this element at number 84 was obtained nine years later by the efforts of the Curie spouses who studied the phenomenon of radiation. Maria Sklodovskaya-Curie tried to find out the cause of strong radiation emanating from certain minerals, and therefore she began working with several rock samples, treating them with all the methods available to her, dividing into fractions and discarding unnecessary. As a result, she received a new substance, which became an analogue of bismuth and the third open radioactive element after uranium and thorium.
Despite the successful results of the experiment,Mary was in no hurry to talk about her discovery. The spectral analysis conducted by a colleague of the Curie spouses also gave no reason to talk about the discovery of a new element. Nevertheless, in a report at a meeting of the Paris Academy of Sciences in July 1898, the spouses reported on the alleged receipt of a substance exhibiting the properties of the metal and suggested that it be called polonium in honor of Poland, the homeland of Mary. This was the first and only case in history when an element that had not yet been reliably identified was already named. Well, the first sample appeared only in 1910.
Polonium is a relatively softsilvery white metal. It is so radioactive that it glows in the dark and constantly heats up. At the same time, its melting point is slightly higher than that of tin - only 254 degrees Celsius. Metal oxidizes very rapidly in air. At low temperatures, it forms a monoatomic simple cubic crystal lattice.
According to its chemical properties, polonium is veryclose to its counterpart - tellurium. In addition, the nature of its compounds is greatly influenced by high levels of radiation. So, reactions involving polonium can be quite spectacular and interesting, albeit quite dangerous in terms of health benefits.
In total, science currently knows 27 (according toother sources - 33) forms of polonium. None of them is stable, and they are all radioactive. The heaviest isotopes (with ordinal numbers from 210 to 218) are found in small quantities in nature, the rest can be obtained only by artificial means.
Radioactive polonium-210 - the most long-livedfrom natural forms. It is contained in small quantities in radium-uranium ores and is formed by a chain of reactions starting with U-238 and lasting about 4.5 billion years, if we talk about the half-life.
1 ton of uranium ore contains isotopepolonium-210 in an amount of about 100 micrograms. They can be distinguished when processing waste, but to obtain a more or less significant volume of the element would have to process a huge amount of material. A much simpler and more efficient method is the synthesis using natural bismuth neutron irradiation in nuclear reactors.
As a result, after some more procedures, polonium-210 is obtained. Isotopes 208 and 209 can also be obtained by irradiating bismuth or lead with accelerated beams of alpha particles, protons or deuterons.
Полоний-210, как и остальные изотопы, является alpha emitters. A group of heavier also emits gamma rays. Despite the fact that the isotope 210 is a source of only alpha particles, it is quite dangerous, it can not be taken by hand and even close at a short distance, because, heating up, it becomes aerosol. Polonium ingestion with breathing or food is also extremely dangerous. That is why the work with this substance takes place in special sealed boxes. It is curious that this element was found in tobacco leaves about half a century ago. The decay period of polonium-210 compared with other isotopes is long enough, and therefore it can accumulate in the plant and subsequently harm the health of the smoker even more. However, any attempts to extract this substance from tobacco were unsuccessful.
Since polonium-210 emits onlyAlpha particles, observing certain precautions, should not be afraid of working with it. The length of these waves rarely exceeds ten centimeters, in addition, they usually cannot penetrate the skin.
However, once inside the body, they causegreat harm to him. When released into the blood, it is quickly spread through all tissues - after a few minutes its presence can be seen in all organs. First of all, it is present in the kidneys and liver, but in general, it is distributed fairly evenly, which can explain its high total damaging effect.
The toxicity of polonium is so great that evensmall doses cause chronic radiation sickness and death after 6-11 months. The main ways of excretion from the body is through the kidneys and gastrointestinal tract. There is a dependence on the method of hitting. The half-life is 30 to 50 days.
Случайное отравление полонием совершенно is impossible. To obtain a sufficient amount of a substance, it is necessary to have access to a nuclear reactor and deliberately enclose the isotope to the victim. The complexity of the diagnosis lies in the fact that there are only a few cases in history. The first victim is the daughter of the discoverer of polonium - Irene Joliot-Curie, who during the research broke the capsule with the substance in the laboratory and died 10 years later. Two more cases occur in the 21st century. The first is the sensational case of Litvinenko, who died in 2006, and the second is the death of Yasser Arafat, in whose possessions traces of a radioactive isotope were found. However, the final diagnosis was not confirmed.
One of the most long-lived isotopes, along with208 and 209, is polonium-210. The half-life (that is, the time during which the number of radioactive particles is halved) is 2.9 and 102 years for the first two, and 138 days and 9 hours for the last two. As for the other isotopes, their lifetimes are calculated mainly in minutes and hours.
The combination of different properties of polonium-210 makesits most convenient of a number for use in various spheres of life. Being in a special metal shell, he can no longer harm his health, but is able to give his energy for the benefit of mankind. So what is polonium-210 used for today?
According to some data, about 95% of the production of polonium is concentrated in Russia, with about 100 grams of the substance being synthesized per year, and almost all of it is exported to the USA.
Существует несколько сфер, в которых применяется polonium-210. First of all, these are spacecraft. With its compact size, it is indispensable as an excellent source of energy and heat. Although approximately every 5 months its efficiency is halved, heavier isotopes are much more expensive to produce.
In addition, polonium is absolutely indispensable in nuclear physics. It is widely used to study the effect of alpha radiation on other substances.
Finally, another application isproduction of devices for removing static electricity for both industry and home use. It is even surprising how such a dangerous element can become almost kitchen utensils, being enclosed in a reliable shell.
